Fortnite Skull Trooper 4K Wallpaper is the name of one of the outfits in Fortnite Battle Royale.
It was introduced as part of the Fortnitemares Update and is a weekly item for the week of Halloween.

Download and exclusive 4K Wallpaper free to use!

This was the first skin in Fortnite Battle Royale with Ghoul Trooper and Renegade, the harvesting tools Reaper and Lucky and the glider Petunia. The first time that you can get this skins was in the Patch 1.8 (the 26th of October). You can not purchase this item anymore as it has expired

It might return to the Item Shop at a later date, most likely Friday the 13th or next Halloween.

Skull Trooper is a reference to a scene in the 1984 movie Karate Kid in which the main character is being chased by a group of enemies in Halloween costumes.

Fortnite is the living, action building game from the developer formerly known as Epic MegaGames. You and your friends will lead a group of Heroes to reclaim and rebuild a homeland that has been left empty by mysterious darkness only known as “the Storm”.

Band together online to build extravagant forts, find or build insane weapons and traps and protect your towns from the strange monsters that emerge during the Storm. In an action experience from the only company smart enough to attach chainsaws to guns, get out there to push back the Storm and save the world. And don’t forget to loot all the things.